Word has been going around for some time now that Apple is going to get rid of the "X" in the naming of its operating system. 9to5Mac reports Apple referred to its desktop operating system as "macOS" in an updated version of the iTunes Connect FAQ. The wording was quickly changed but it's widely expected that the rebrand to "macOS" will be announced at next week's WWDC.
This isn’t the first time Apple has mistakenly referred to Mac OS X as macOS. Originally in March, we discovered a framework in OS X 10.11.4 that referred to the operating system as macOS. The following month, Apple launched a new environmental webpage on which it referred to the operating system as MacOS.
There’s still some uncertainty as to whether the rebrand will be to MacOS or macOS, but at this point we’ve seen two leaks that use the latter and only one that uses the former. Although while iOS, tvOS, and watchOS all use lowercase letters, the difference could be that Mac is a proper noun while ‘tv’ and ‘watch’ technically aren’t without the Apple stuck in front of them.